Fuse device.



E. 0. SCHWEITZER & N. J. CONRAD.

FUSE DEVICE.

APPLICATION FILED DEC. 20 1913- PatentedApr. 24, 1917.

UNITED STATES PATENT OFFICE.

EDMUND O. SCHWEITZER AND NICHOLAS J. CONRAD, OF CHICAGO, ILLINOIS, ASSIGNORS TO SCHWEITZER & CONRAD, A CORPORATION OF ILLINOIS.

FUSE DEVICE.

Specification of Letters Patent.

Application filed December 20, 1913. Serial No. 807,811.

To all whom it may concern:

Be it knownthat we, EDMUND O.

SCHWEITZER and NICHOLAS J. CONRAD, citi- 6 cago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Fuse Devices, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

Our invention relates to fuse devices, and especially to fuses for taking care of extra high potentials.

Prominent objects of the invention are to provide a simple, practical and satisfactory fuse device of the class mentioned; to arrange for the accurate and effective operation of the same; to permit variation of the size of the fuse as desired; to secure a high degree of rapidity in the operation of the device; to afford effective sealing arrangements for properly sealing the contents of the fuse casing; and to secure the above and other desirable results in a simple and expeditious manner.

In the accompanying drawings Figure 1 is a longitudinal sectional view of a fuse embodying our present invention;

Fig. 2 is a similar view of the same in process of operating;

' Fig. 3 is a plan view of the same;

Figs. 4: and 5 are cross sections taken on lines 41 and 55 respectively, in Fig. 1.

Referring to the drawings, 1 is a tubular casing, preferably cylindric in form and preferably made of glass or other similar material. A tubular metal band 2 is arranged around the outside of the upper end of the tube 1', and a cap piece or plate 3 is mounted upon the top of the band or ferrule 2, being secured thereto so as toform a closure or disk vent. erably provided with an opening which is sealed by solder 4. Shellac 5 is preferably interposed between the ferrule 2 and the upper end of the tube 1, so as to cement the "ferrule to the glass tube, the shellac preferably being introduced in melted condition. The lower end ofthe tube 1 is provided with a metal cap 6, the-sides of which extend up the sides of the lower end of the tube, said cap piece closing said lower end of the tube. Shellac 7 is preferably introduced between the lower end of thetube 1 and the cap leakage.

The disk 3 is prefpiece 6, said shellac being preferably introduced in a melted state and serving to effectively seal the lower end of the tube. The bottom of the cap 1 is provided with a tapped opening which receives a screw 6*, the purpose of the opening being to permit the filling of the tube 1 with liquid and then permitting said tube to be closed by inserting the screw. Solder 6 is preferably put around the outer end of the screw 6, so as to seal the device effectively against A suitable liquid 8, preferably carbon tetra-chlorid, or the like, is introduced within the interior of the tube 1 and this liquid preferably immerses the fuse elements, as shown. A metal link 9 ex tends down from the disk 3, and a fuse 10 and reinforcing wire or device 11 are connected to the lower end of the link 9. The link 9 is preferably made with a flattened portion 9, which is above the disk 3, and a pin 12 is preferably passed through an aperture in said flattened portion 9 .and soldered to the disk 3 by solder 13, Fig. 3. The link 9 is also desirably made with another flattened portion' 9 between its ends, and also with a third flattened portion 9 at its lower end. The flattened portions 9 and 9 are provided with apertures 14 and 15, respectively. The fuse 10 and reinforcing wire 11 which is preferably of steel, although it may be of other material, are wound about the upper portion of the link 9 between the flattened portions 9 and 9 and are then extended downward and through the aperture 14, and thence downwardly and through the aperture 15, and thence downwardly. their lower ends being connected to a metallic link or terminal member 16. The upper end of the fuse 10 is preferably soldered to the link 9'by solder 17. The portions of the fuse and reinforcing wire between the links 9 and 16 are preferably confined in an envelop or covering preferably in the form of a block or piece 18 of material such as cork. Below the block or mass 18 we preferably arrange a funnel member 19 having a tapering opening 20 which member hasthe effect of di recting a liquid stream upon the arc, and hence may be termed a liquid director. The link 16 is conveniently connected with the member 19 by a cross pin 21, said link extending thence downwardly and being connected with a coiled spring 22 which acts Patented Apr. 24, 1917.

upon the link 16, and thereby upon the fuse 10 and reinforcing wire 11. The lower end of the spring 22 is connected to the cap 6 which also serves as the terminal of the device. Thus the circuit is made from the disk 3 which with the ferrule or band 2 serves as one terminal of thedevice, through the link 9 and thence through the fuse and reinforcing wire to the link 16, and from the latter through the spring 22 and also through a wire 23 extending down from the link 16, to the cap 6 which forms the other terminal of the device.

In operation the fuse carries the major portion of the current and therefore when it blows all the current is thrown upon the reinforcing wire and as that amount of current is very greatly in excess of the current normally carried by that wire, said wire also blows, thereby releasing the spring 22 which thereupon contracts, drawing the member 19 downwardly, as shown in Fig. 2, and causing a stream of arc extinguishing liquid to be thrown or directed upon the fuse terminal formed by the upper end of the link 16 and upon the space between the fuse terminals, thereby extinguishing or preventing the arc. Thus the circuit is quickly opened, and

an are effectively prevented. The presence of the reinforcing wire or device in connection with the fuse permits the strain of the spring 22 to be taken up by said reinforcing wire, and the fuse to be accordingly relieved. The arrangement of the cork 18 about the fuse wire 10 and the reinforcing wire 11 permits of a much sharper definition of the limits of current flow, than has heretofore been possible where a reinforcing element has been used.

In prior devices where no reinforcing element is employed, the heat that is develo ed in the fuse wire is conserved by the insu ating character of the cork and the fuse may be elongated by the tension of the spring before the desired limit of current is reached. This may appreciably change the capacity of the fuse itself particularly where the operation is repeated.

.In our present device where a reinforcing wire is employed the fuse, even though it is embraced by the cork, does not stretch due to the support of.the tension by the reinforcing wire which has a higher melting or softening point. But when the fuse begins to melt the heat developed is conserved by the cork and is transferred directly by contact to the reinforcing wire. Thus it can be seen that the disadvantage of softening and elongation of the fuse wire by the heat retained by the surrounding cork is obviated but a much quicker complete rupture of both the reinforcing'ifire. and the fuse wire is obtained, and a sharper definition of the capacity of the fuse is insured. The size and character of the reinforcing wire or device can, of

course, be varied, thereby permitting the device to be made as sensitive and as quick or slow acting as desired, and also permitting the spring 22 to be made as strong as desired.

It will be understood that changes and modifications may be made without depart ing from the spirit of the invention.

What we claim is:

1. A device of the class specified comprising in combination, a tube of insulating material, metal terminals at the opposite ends of said tube, a, fuse and a reinforcing wire of high melting temperature between said terminals, a spring acting upon said fuse and wire, and a cork envelop confining said fuse and'wire and holding the same in contact with each other 2. In a fuse device, the combination with fuse terminals, one of which is movable, of a fuse extending between said terminals, a spring acting upon the movable terminal to separate it from the other and thereby lengthen the fuse gap upon the operation of the fuse, and a reinforcing metallic conductor of higher tensile strength and higher melting point acting to relieve the tension of said spring upon said fuse.

3. In a fuse device the combination with terminals for the fuse, one of which is movable relatively to the other, of a fuse extending between said terminals, a sprin pulling directly upon the movable termina to separate it from the other and thereby lengthen the fuse gap, and a reinforcing conductor also extending between said terminals and acted upon by said spring, said reinforcing conductor consisting of a wire of relatively strong material having a rela tively high resistance and higher melting point.

4. In a fuse device,the combination of a tubular casing made of insulating material, a metallic ca at one end of said casing said cap forming a terminal of the fuse device, a metallic terminal member extended through said cap into the interior of the casing, the inner end of said member forming a fuse terminal, a fuse and reinforcin" conductor connected and secured to sai metallic member and extended from the end of the same into the casing, a movable terminal connected to the other end of said fuse and metallic reinforcing conductor, a spring connected with said movable terminal, and are extinguishing liquid within said tubular member.

5. The combination with a fuse casing of a metal disk 3, a link 9 passing through said disk into the interior of said casing, 21. pin 12 passing through an aperture in said link, and soldered to the outer surface of said disk 3, said link 9 being provided with a plurality of transverse apertures in its portion within said casing, a fuse wire wound around said link and passing through the apertures therein, and a terminal for the other end of the fuse wire.

6. The combination with a fuse casing of a metal disk 3, a link 9 passing through said disk into the interiorof said casing, a pin 12 passing through an aperture in saidlink and soldered to the outer surface of sai disk 3, said link 9 being provided with a plurality of transverse apertures in its portion within said casing, a fuse wire wound around said link and passing through the apertures therein, a terminal for the other end of the fuse wire, and a reinforcing wire also wound about said link and passed through the apertures thereof and to the other fuse terminal alongside of said fuse. 7. In a fuse device a stationary terminal member, a movable terminal member, a coil spring normally under. tension connected to v the movable terminal member, a fuse for conducting the major part of the current that passes between the terminals, a small wire connected in shunt of said fuse; said wire being of higher tensile strength, higher.

resistance and higher melting point than the fuse and being mechanically connected to sustain the direct pull of the spring.

8. In a fuse device a stationary terminal member, a movable terminal member, a fuse wire extending between said members, a reinforcing wire of higher tensile strength, higher resistance and higher melting temperature than the fuse, extending between the said members and a resilient member inclosing both the fuse and the reinforcing wire and holding them substantially in contact with each other.

In witness whereof, we hereunto subscribe our names this 10th day of December,

EDMUND o. SCHWEITZER. NICHOLASJ. CONRAD.

Witnesses:

A. L. J was, HAZEL ANN Jonas. 

